Treatment of hydrocarbon oils



p ,1934- c. H. ANGELL v 1,972,914

TREATMENT OF HYDROCARBON OILS Filed Dec. 19, 1931 FURNACE INVENTORCHARLES H. ANGELL mww Patented Sept. 11, 1934 UNITED STATES,

TREATMENT OF HYDROCARBON OILS Charles H. Angel], Chicago, Ill.,

assignor to Universal Oil Products Company, Chicago, I'lL, a corporationof South Dakota Application December 19, 1931, Serial No. 582,021"

1 Claim.

This invention relates to the treatment of hydrocarbon oils and moreparticularly refers to the treatment of crude oils containing gasolinefor the purpose of simultaneously topping I the crude, reforming itsnaturally contained gasoline components to improve their quality andconverting its heavier components for the production of substantialyields of lighter products.

10. The treatment of relatively heavy hydrocarbon oils under elevatedtemperatures and substantial super-atmospheric pressures to effect theirconversion into substantial yields of more desirable lower boilingproducts, such as motor fuel 15, preferably of relatively high antikncckvalue,

' is now a well known partcf the refining art.

The charging stock for such processes usually comprises oils from whichany naturally con tained gasoline has been previously extracted bydistillation although some cracking processes incorporate means fortopping crude oils, i. e., removing their naturally contained gasolinefractions in the same system in which their heavier components arecracked. Most straightrun gasoline, i. e., gasolines existing in anatural state in petroleum, are of such poor antiknock value as to beunsuitable for use as motor fuel in the modern high compression engineswithout blending or resorting to the use of knock inhibitors. A morerecent development in the cracking art are processes for reformingmaterials of substantially motor fuel boiling range (straightrungasoline, for example) primarily to improve their antiknock qualitywithout substantially altering their boiling range.

It is the purpose of the-present invention to incorporate-all of theabove described operations, namely, topping, cracking and reforming in asingle improved. process and apparatus.

An outstanding feature of the inventionis the simplicity of the processand apparatus by means of which all of the operations mentioned areaccomplished.

The primary principles of the invention comprise introducing-a petroleumoil containing desirable light components such as gasoline into thereaction zone: of a cracking system where, by means of the heat impartedthereto by direct contact with the conversion products of the system,said relatively light components are substantially vaporized and, underthe elevated temperature and super-atmospheric pressure conditionsmaintained in thereaction zone,.their antiknock value is materiallyimproved and thence subjecting hea ier components of the raw oil toconversion in the same cracking system for the production of substantialyields of desirable light products such as motor fuel.

The principles of the invention are applicable to many types of crackingsystems and are therefore not limited to use in any one particular typeof equipment. However, when it is desired to produce fueloil as theresidual prodnot of the system, the type of cracking system outlined inthe following specific embodiment has been found entirely suitable.

The invention may comprise, in one of its more specific embodiments,subjecting hydrocarbon oil to conversion conditions in a heatingelement, introducing the heated oil into an enlarged reaction zone,maintaining substantial super-atmospheric pressure within said heatingelement and reaction zone, subjecting vaporous materials in saidreaction zone to continued con- 7 version for a predetermined time whilequickly 7,5 separating therefrom non--vaporous products, withdrawingboth vaporous and non-vaporous materials from said reaction zone to .avaporizing zone, preferably maintained under a substantially reducedpressure, wherein further vaporization of said non-vaporous materialsfrom said reaction zone and final separation of vaporous products iseffected, subjecting vapors from said reduced pressure zone tofractionation whereby their insufliciently converted components arecondensed, being returned therefrom to the heating element for furtherconversion, supplying to the system as rawoil charging stock,hydrocarbon oil containing components of motor fuel boiling-range andintroducing said oil into said reaction zone where, by direct contactwith relatively hot oil from said heating element, its'substantialvaporization is effected and the .antiknock value of said components ofsubstantially motor fuel boiling range is materially-improved.Preferably a residual oil comprising the relatively heavy non-vaporousconversion productsof the systemand the relatively heavy components ofthe charging stock, remaining unvaporized, are withdrawn from thereduced pressure vaporizing zone of the system and a distillate ofsubstantially motor fuel boiling range and of good antiknock qualitycomprising reformed straight-rungasoline and motor fuel resulting fromthe conversion of heav ier component -of the chargingstockis removedfrom the fractionator as the light distillate product of the system. 1

- Preferably at least a portion of the heat required,forwaporization-ofthe charging stock is recovered by indirect contact of the chargingstock with relatively hot vaporous and/or liquid products of the system,prior to its introduction into the reaction zone.

The attached diagrammatic drawing illustrates one specific form ofapparatus to which the principles of the process of. the invention tionchamber 5. Chamber 5 is also preferably maintained at a substantialsuper-atmospheric pressure and the materials remaining vaporized in thiszone are subjected to continued conversion for a predetermined timeWhile non-vaporous materials are quickly separated from the vapors,gravitating to the lower portion of the chamber to be removed therefrom,together with the slower moving vapors which have reached the exit,passing through line 6 and valve" 7 to vaporizing chamber 8.

vaporizing chamber 8 is preferably maintained at a substantially reducedpressure relative to that employed in chamber 5 by means of which, dueto the liberation of latent heat,

. non-vaporous materials removed from chamber 5 are further vaporizedand cooled. Oil remaining unvaporized in chamber 8 is removed therefromas the residual product of the system through line 9 and valve 10 tocooling and storage or to any desired further treatment. Vaporousproducts from chamber 8 pass through line 11 and valve 12 tofractionator 24 where their insufficiently converted components arecondensed, collecting as, reflux condensate in the lower portion of thefractionator to be Withdrawn therefrom through line 13 and valve 14 topump 15 and supplied through line 16 and valvel'? to heating element 1for further conversion.

Raw oil charging stock for the process, which comprises a hydrocarbonoil containing a sub: stantial proportion of components boiling withinthe range of motor fuel, is supplied through line 18 and valve 19 topump 20 from which it is fed through line 21 and valve 22 to preheatingcoil 23. Preheating coil 23'is located Within fractionator 24, thecharging stock passing therethrough receiving heat by indirect contactwith the relatively hot vapors in this zone. The preheated raw oilpasses through line 25 and valve 26 into reaction chamber 5, comminglingtherein with the heated on fromheating element 1 and being substantiallyvaporized. It will be understood that other well known means ofpreheating the raw oil charging stock may be employed in conjunctionwith or instead of the means illustrated. Such other means may comprise,for example, indirectly contacting the raw oil with residual oilfr'omfchamber 8 and/or with the material passing from chamber 5 tochamber 8. I

-;Relatively light vapors of the desired end boiling point, preferablyfalling within the boiling range of motor fuel and comprising both themotor fuel components of the charging stock, the antiknock value ofwhich has been materially improved by subjection to the con versionconditions in chamber 5, and cracked motor fuel resulting fromconversion of the heavier components of the charging stock, areWithdrawn from fractionator 24 through line 27 and pass through valve 28to condensation and cooling in condenser 29. Distillate andtincondensable gas passes from condenser 29 through line 30 and valve 31to collection in receiver 32. Uncondensable gas is released fromreceiver 32 through line 33 and valve 34. Distillate is withdrawn fromreceiver 32 through line 35 and valve 36. A portion of the distillatemay, if desired, be withdrawn from receiver 32 and recirculated, by wellknown means not shown in the drawing, to the upper portion offractionator 24 to control the vapor outlet temperature and assistfractionation of the vapors in this zone.

Pressures employed within the system may range from substantiallyatmospheric to superatmospheric pressures as high as 2000 pounds per sq.in., or more. Conversion temperatures employed may range from 800 to1200 F., more or less. Preferably conversion temperatures of the orderof 900 to 1050" F. are employed in the heating element while somewhatmilder conversion temperatures of the order of 750 to 950 F. areemployed in the reaction chamber. Both the heating element and reactionchamber preferably utilize substantial super-atmospheric pressures ofthe order of 100 to 500 pounds or more per sq. in. The vaporizing zoneand succeeding fractionating, condensing and collecting portions of thesystem preferably utilize substantially reduced pressures of the orderof substantially atmospheric to 100 pounds per sq. in., or thereabouts.I

As a specific example of the operation of the process of the invention,a Mid-continent crude oil containing about 30 percent of gasoline havingan antiknock value approximately equivalent to a blend of 20 percentbenzol and percent straight-run Pennsylvania gasoline is the raw oilcharging stock supplied to the system. The charging stock is preheatedby the heat recovered within the cracking system and thence introducedinto the reaction chamber. Reflux condensate from the fractionator ofthe system is subjected in the heating element to a tem foo iii.

perature of approximately 970 F. The stream of heated oil passing fromthe heating'element to the reaction chamber is cooled by theintroduction of charging stock to a temperature of approximately 900 F.as it enters the reaction chamber. The heating element and reactionchamber are maintained under a super-atmosphericpressure ofapproximately 500 pounds per sq. in. The pressure in the vaporizingchamber is reduced to approximately 35 pounds per sq. in., whichpressure is substantially equalized in the succeeding fractio'nating,condensing and collecting portions of the system.- This operation" mayyield, based on the charging stock, approximately '75 percent of motorfuel having an antiknock value approximately equivalent to a blend of 60percent benzol and40 percent straight-run Pennsylvania gasoline.Inaddition about 15 percent of good quality residual oil suitable forsale as fuel may be obtained, the

action zone maintained under cracking conditions of temperature andsuperatmospheric pressure, commingling crude oil containing naturalgasoline, without prior heating thereof to cracking temperature, withthe heated distillate being discharged into the upper portion of thereaction zone, passing the vaporous and liquid components of the thuscommingled oils downwardly in unobstructed flow thru the reaction zone,removing the vapors and liquid oil as a mixture from the lower portionof the reaction zone, the liquid being Withdrawn at a rate adequate toprevent substantial accumula tion of liquid in the reaction zone,reducing the pressure on the mixture withdrawn from the reaction zoneand separating the same into vapors and residue, dephlegmating the thusseparated vapors to condense fractions thereof heavier than gasoline,supplying resultant reflux condensate to the heating zone as saidhydrocarbon distillate, and finally condensing the dephlegmated vapors.

CHARLES H. ANGELL.

